Original Article

European Journal of Clinical Nutrition (2009) 63, 1106–1114; doi:10.1038/ejcn.2009.30; published online 27 May 2009

The glycaemic index values of foods containing fructose are affected by metabolic differences between subjects

Contributors: TMSW conceived of the study, AJ, VV and JC contributed to its ultimate design. TMSW, AJ and VV obtained funding. TMSW analysed the data and drafted the manuscript which AJ, VV and JC reviewed for critical content.

T M S Wolever1, A L Jenkins1, V Vuksan1 and J Campbell1

1Glycemic Index Laboratories, Inc., Toronto, Ontario, Canada

Correspondence: Dr TMS Wolever, Glycemic Index Laboratories, Inc., 36 Lombard Street, Suite 100, Toronto, Ontario, Canada M5C 2X3. E-mail: thomas.wolever@utoronto.ca

Received 28 October 2008; Revised 10 February 2009; Accepted 15 April 2009; Published online 27 May 2009.





Glycaemic responses are influenced by carbohydrate absorption rate, type of monosaccharide absorbed and the presence of fat; the effect of some of these factors may be modulated by metabolic differences between subjects. We hypothesized that glycaemic index (GI) values are affected by the metabolic differences between subjects for foods containing fructose or fat, but not for starchy foods.



The GI values of white bread (WB), fruit leather (FL) and chocolate-chip cookies (CCC) (representing starch, fructose and fat, respectively) were determined in subjects (n=77) recruited to represent all 16 possible combinations of age (less than or equal to40, >40 years), sex (male, female), ethnicity (Caucasian, non-Caucasian) and body mass index (BMI) (less than or equal to25, >25kg/m2) using glucose as the reference. At screening, fasting insulin, lipids, c-reactive protein (CRP), aspartate transaminase (AST) and waist circumference (WC) were measured.



There were no significant main effects of age, sex, BMI or ethnicity on GI, but there were several food × subject-factor interactions. Different factors affected each food's area under the curve (AUC) and GI. The AUC after oral glucose was related to ethnicity, age and triglycerides (r 2=0.27); after WB to ethnicity, age, triglycerides, sex and CRP (r 2=0.43); after CCC to age and weight (r 2=0.18); and after FL to age and CRP (r 2=0.12). GI of WB was related to ethnicity (r 2=0.12) and of FL to AST, insulin and WC (r 2=0.23); but there were no significant correlations for CCC.



The GI values of foods containing fructose might be influenced by metabolic differences between –subjects, whereas the GI of starchy foods might be affected by ethnicity. However, the proportion of variation explained by subject factors is small.


metabolism and nutrition, nutrition physiology, dietary carbohydrates, humans, methodology, glycemic index

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